Issue #15056: imp.cache_from_source() and source_from_cache() raise
NotimplementedError when sys.implementation.cache_tag is None.
Thanks to Pranav Ravichandran for taking an initial stab at the patch.
diff --git a/Lib/test/test_imp.py b/Lib/test/test_imp.py
index 7b0c727..a660278 100644
--- a/Lib/test/test_imp.py
+++ b/Lib/test/test_imp.py
@@ -231,6 +231,8 @@
tag = imp.get_tag()
+ @unittest.skipUnless(sys.implementation.cache_tag is not None,
+ 'requires sys.implementation.cache_tag not be None')
def test_cache_from_source(self):
# Given the path to a .py file, return the path to its PEP 3147
# defined .pyc file (i.e. under __pycache__).
@@ -239,6 +241,12 @@
'qux.{}.pyc'.format(self.tag))
self.assertEqual(imp.cache_from_source(path, True), expect)
+ def test_cache_from_source_no_cache_tag(self):
+ # Non cache tag means NotImplementedError.
+ with support.swap_attr(sys.implementation, 'cache_tag', None):
+ with self.assertRaises(NotImplementedError):
+ imp.cache_from_source('whatever.py')
+
def test_cache_from_source_no_dot(self):
# Directory with a dot, filename without dot.
path = os.path.join('foo.bar', 'file')
@@ -283,6 +291,9 @@
imp.cache_from_source('\\foo\\bar\\baz/qux.py', True),
'\\foo\\bar\\baz\\__pycache__\\qux.{}.pyc'.format(self.tag))
+ @unittest.skipUnless(sys.implementation.cache_tag is not None,
+ 'requires sys.implementation.cache_tag to not be '
+ 'None')
def test_source_from_cache(self):
# Given the path to a PEP 3147 defined .pyc file, return the path to
# its source. This tests the good path.
@@ -291,6 +302,13 @@
expect = os.path.join('foo', 'bar', 'baz', 'qux.py')
self.assertEqual(imp.source_from_cache(path), expect)
+ def test_source_from_cache_no_cache_tag(self):
+ # If sys.implementation.cache_tag is None, raise NotImplementedError.
+ path = os.path.join('blah', '__pycache__', 'whatever.pyc')
+ with support.swap_attr(sys.implementation, 'cache_tag', None):
+ with self.assertRaises(NotImplementedError):
+ imp.source_from_cache(path)
+
def test_source_from_cache_bad_path(self):
# When the path to a pyc file is not in PEP 3147 format, a ValueError
# is raised.